The rioting that erupted in Ferguson, Missouri, over the weekend calls to mind Chicago Mayor Richard Daley's 1968 gaffe: "The policeman is not here to create disorder. The policeman is here to preserve disorder." In Ferguson, the police are doing an outstanding job of that.
That's partly why Missouri Governor Jay Nixon was right to call in the National Guard today. Yet he must know that the move will not quell the anger among protesters, who are motivated not only by a sense of injustice over an unarmed teenager's death but also out of frustration with a truculent police force. Only when political leaders do a better job of holding police accountable -- an urgent necessity in Ferguson right now, and a priority nationwide -- will tensions truly begin to ease.